Vesico-ureteral Reflux

Background

Patients that have fever associated with a urinary tract infection by definition have a kidney infection or pyelonephritis. 1/3 of children with a urinary tract infections associated with a fever have vesio-ureteral reflux.

Causes

Vesico-ureteral reflux (VUR) is a condition where urine moves up from bladder towards the kidneys. Urine usually travels in a forward fashion; it is produced by the kidneys and travels down to the bladder where it dwells prior to being peed or voided out. With VUR the urine can travel in a backward or retrograde fashion back of the ureter toward the kidney. Vesicorueteral reflux is graded 1-5.

Historically, it was thought the refluxing urine caused damage to the kidneys. We know now that the damage is created if infected urine in the bladder is refluxed up to the kidneys potentially causing a kidney infection or pyelonpehritis.

When a kidney becomes infected there is a 30% chance that the kidney can form a scar after the infection. Scarring can result in potential kidney dysfunction and over the long term hypertension (high blood pressure).

Diagnosis and Evaluation

The diagnosis and work up for reflux includes:

history and physical exam

urinalysis and culture and review of prior urine culture findings

renal bladder ultrasound

+/- renogram

+/- VCUG

Most children with a urinary tract infection associated with a fever will get a renal ultrasound then will have a renogram 6 months following the infection. The renogram looks for renal scarring. If there are findings suspicious for scarring then a VCUG will be considered to look for reflux.

Vesicoureteral reflux is diagnosed with a VCUG (voiding cystourethrogram). A VCUG is where contrast is put into the bladder via a catheter or tube. X-Rays are then taken to see if the urine travels back up the ureter. It is graded from I to IV based on the

Grade I - reflux into a non-dilated ureter (but not into the kidney)

Grade II - reflux into renal pelvis and calyces of the kidney with no dilation

As children grow, the grade of reflux decreases. As a result, the majority of children will outgrow their reflux over time. The important thing is for children to outgrow their reflux safely. Often this is facilitated with the use of low dose daily antbiotic prophylaxis to prevent kidney infection while children grown

The use of antibiotic prophylaxis was controversial; however, a recent study (RIVUR trial published in the New England Journal of Medicine 2014) has shown a significant reduction in urinary tract infections associated with fever with the use of a low dose antibiotic taken daily. The incidence of urinary tract infections associated with a fever without the use of a daily antibiotic was 25% with the use of a daily prophylaxis was 12%. This represents a 50% reduction of overall incidence of febrile urinary tract infections. As a result, this is considered for pediatric patients.

DEFLUX Therapy

DEFLUX is a substance that is injected below the opening of ureter to prevent urine from refluxing up the ureter. The patient is brought to the operating room and while the patient is asleep, a small scope is used to look into the bladder. A needle is passed through the scope and is used to inject the DEFLUX material. Deflux is effective in preventing reflux in roughly 80% of cases.

Ureteral Reimplantation

Ureteral reimplantation invloves a surgery where the ureter is moved to a new location within the bladder to prevent it from refluxing. Currently, DEFLUX injection is usually used a first line; however, reimplantation is used for patients that fail deflux therapy or have other anatomic problems in the bladder that require surgical intervention.

Author : Dr J Mickelson - Last edited Oct 2015

Web Site Links

Antibiotic Prophylaxis for Children with Vesicoureteral Reflux (The RIVUR Trial). NEJM, vol 370, No 25, June 2014.